Crucible smelting-furnace.



No. 722,831, PATENTED MAR. 1'7, 1903. 0. FORSBAGH & E. GLERG. ORUGIBLESMELTING FURNACE.

APPLICATION FILED JAN. 24, 1901.

N0 MODEL.

a a a r: i 0 j g 0 Z a 27/ )0 t Z a r g f 7 m NORRIIS PETERS cu,Pmm-uma. WASHINGTON, n. c.

UNITED STATES PATENT OFFICE.

OTTO FORSBACH AND EDUARD OLERO, OF MULHEIM-ON-THE-RHINE, GERMANY.

CRUCIBLE SMELTlNG-FURNACE.

SPECIFICATION formingpart of Letters Patent No. 722,831, dated March 17,1903. Application filed January 24, 1901. Serial No. 44,507. (No model.)

To all whom it may concern:

Be it known that We, OTTO FORSBACH and EDUARD CLERG, subjects of theEmperor of Germany, residing at Miilheim-on-the-Rhine, Rhineland,Germany, have invented certain new and useful Improvements .in Cruciblesmelting-Furnaces, of which the following is a specification.

In the crucible smelting-furnaces hitherto known the heating-gaseseither played around the crucible containing the substance to besmelted, the said crucible being in this case over the fire in thefurnace, or the heatinggases were conducted through the substance to besmelted, the crucible in this case being above the furnace and areceiving-crucible being provided for the melted substance.

According to the present invention the furnace is so constructed thatthe smelting takes place sim ultaneously in two crucibles,around one ofwhich the heatingases play, the latter after imparting part of theirheat to the first crucible or the substance therein being conductedpartially around the second crucible and partially through the samebefore arriving at the chimney. The heating-gases are thus morethoroughly utilized, the smelt ing is efiected more rapidly, and whenthe substance to be smelted has once been put in and the furnace setgoing the latter requires hardly any attendance.

In the annexed drawings, Figure l is a vertical sectional view of ourinvention. Fig. 2 is a like view of a modification. end view of thesupporting-frame for the crucible-receptacle. Fig. 4 is a side viewthere of. Fig. 5 is a plan view of the perforated plate within thesupporting-frame.

The furnace represented by Fig. 1 com prises two parts placed one abovethe other, both the upper and the lower part being surrounded by asingle sheet-metal jacket 70. \Vithin this jacket and held together bythe same are fire-brick jackets b and Z, of which the former surroundsthe crucible and grate and the latter forms in itself a receiving pot orchamber receptacle in the shape of an inverted truncated cone open atthe bottom. The crucible-receptacle t rests upon a base or frame to,supporting at its upper part a grate '1', consisting of fixed or loosebars.

Fig. 3 is an' The heating can be effected in any suitable manner; but asa rule it will be done by cokefiring, and this method is represented inthe drawings, the lower part of the lower crucible 25 being surroundedby a layer of coke.

In the sheet-metal and fire-brick jackets b a suitable number ofinclined openings h are provided near the top for the purpose ofinserting coke without interrupting the smelting process, the saidopenings being closed from the outside by means of lids, doors, or thelike.

The upper part of the furnace consists of a removable and portable ortiltable fire-brick receiving-pot Z, surrounded by a metal jacket is,this receiving-pot, like the one inside the furnace, serving to receivethe material to be smelted. At the upper part of this receiving-pot andat the side thereof a channel 0 is provided to conduct the heating-gasesto the chimney, and the crucible is provided at the top with a removablewell-fitting coverp, having a handle 19.

The method of using this furnace is as follows: When the fuel has beenignited, the smelting-crucible if is inserted and the space around thelatter is filled with coke. Thereupon the receiving-pot is put intoposition and the gaps between the bottom of the said crucible and theiron ring upon the lower part are closed with clay. The crucible havingbeen inserted full of material, the receiving-pot is now filled to therequired extent and the cover 1) put on and well closed. Thereceiving-pot can also be put on already filled. The flame andfurnace-gases first heat the smelting-crucible, then rise and pass alongsame and mingle above it with the vapors and gases generated therein bythe smelting. They then pass on their way to the chimney or the channel0 through the material in the receiving pot and smelt that also. Thesmelted material accumulates in the lower crucible. In charging thecrucibles the quantities are so calculated that after smelting the lowercrucible will be sufficiently filled, so that during the process theyneed not be recharged and the furnace requires no attendance except forreplenishing with fuel. This constitutes a very considerable technicaladvance. As the furnace need not be opened during the smelting processand no heat is lost, the smelting process is more rapid and requiresless fuel.

The smelting material in the receiving-pot can be kept in place eitherby the shape of the latter, especially the narrowing of its loweropening, or by wedging in large pieces. By this arrangement the spacebetween the upper edge of the lower crucible and the lower opening ofthe receiving-pot remains completely free.

For discharging the furnace the upper part is removed and the crucibletaken out.

The furnace represented in vertical section in Fig. 2 is moreparticularly intended for the smelting of filings, brass rubbish, andthe like and generally for smaller purposes. The lower part of thisfurnace is similar to that of the one described hereinbefore, exceptthat it is provided with a chamber a, formed by too sheet-metal jackets,which chamber contains compressed air to be conducted to the fire, andthat it rests upon a pivoted plate or the like (1, carried by supports0. The upper part of this furnace is slightly diflferent. The fire-brickcrucible Z is surrounded by a firebrick jacket 0 of the same diameter asthe fire-brick jacket I) of the lower part and closed at the top by acover p. The outer wall of the upper crucible is provided withsupporting-plates q, between which the heating-gases pass, so that theheating-gases do not pass through the upper crucible, but around it. Thesaid gases accumulate above the upper crucible Z under the cover 19 andmust then, in order to reach the chimney through the channel 0, enterthe upper crucible Z, thus passing through part of the material to besmelted. The heating-gases thus play around both crucibles and must passthrough a portion of the upper one before they can escape. The method ofusing this form of the furnace is exactly identical with that of theform first described. The upper crucible can either be put on by itselfor with its jacket.

The two crucibles are charged in exactly the same manner as describedwith reference to the other form of the furnace; but the annular spacebetween the fire-brick jacket b and the cone of fire-bricks e is filledwith a layer 9 of clay or wet sand or the like in order to prevent theentrance of air at the edge of the floor-plate d and to protect thelatter from overheating. Upon this layer of clay or the like a layer ofcoke flies. The entrance of compressed air from the chamber a takesplace through a number of tapering horizontal pipes or channels 1',having their smaller ends adjacent to the crucible. When the supports 0have been removed, the plate (1 can be turned down and slag and the likeremoved.

In many cases it is desirable to obtain a fine I flame by thecombustion. This is achieved by means of the following arrangement,(represented in Figs. 3 to 5:) Instead of the plate (1 closing the lowerorifice of the furnace, Fig. 2, a base or frame can be used, asdescribed in connection with Fig. 1, the said base being suitablymounted below the the brick b andcarrying at the top a grate 0". At theside of the frame it, which is closed on all sides, is a tube 41;,through which air is pressed in. At half the height of the frame andabove the air-admitting tube the former contains a plate .9 withperforations 10. Both the number and size of the holes to can be chosenat will and depend upon the purpose in view. The air admitted by thetube a: is compelled to pass through the holes in the plate 3 and isheated in doing so, and also while in the space between the said plateand the grate 1' and in passing through the grate and the fuel produce afine flame. This base or frame a owing to its location becomes heated,and consequently the air in passing there-.

through is heated before entry into the furnace. When the base u, isemployed, the plate dand the channels tare dispensed with.

Having now particularly described and ascertained the nature of our saidinvention and in what manner the same is to be performed, we declarethat what we claim is 1. In a crucible smelting-furnace, a cruciblesuitably supported above the grate-bars with a receiving portionarranged above the crucible and communicating therewith, the receivingportion having an outlet extending thereinto above the material in thereceiving portion, a cover arranged on the receiving portion, means forpermitting the fuel to be fed around the crucible, the heat rising fromthe fuel, entering the receiving portion, directly engaging the materialin the receiving portion previous to its exhaust through the saidoutlet, substantially as described.

2. In a crucible smelting-furnace, a crucible suitably supported abovethe grate-bars, a jacket surrounding the crucible, a receiving-potcarried by the jacket and communicating with the crucible, there being aslight space between the lower end of the receiving-pot and theupper endof the crucible, an outlet located in the side of the receiving-pot anda cover carried by the pot, the fuel being located around the crucibleand the heat rising and entering in the said space between the crucibleand receiving pot, passing through the material in the pot andexhausting through the outlet, substantially as described.

In witness whereof we have hereunto set our hands in presence of twowitnesses.

OTTO FORSBAOH. EDUARD OLERO. Witnesses:

J OHANN WELLER, CHARLES LESIMPLE.

